This invention relates to coffee and more particularly to decaffeinated coffee.
The major concern of decaffeinated coffee producers has long been the desire to achieve rapid efficient removal of caffein from green coffee without deleteriously affecting the eventual coffee product produced from the decaffeinated coffee. Thus for example, while extremely high temperatures will generally increase decaffeination rates it is at the expense of damaging the flavor and aroma components of the green coffee resulting in a final coffee product which does not closely resemble its undecaffeinated counterpart.
Decaffeination processes employing an organic solvent for caffeine have the advantage of achieving caffeine removal in a relatively short time; however, direct contact of green coffee with solvent may be undesirable due to the possibility of amounts of solvent remaining in the coffee and thereby adversely altering the flavor of resultant coffee product. Further, caffeine-solvents are also found to remove amounts of desirable waxes and oils from the green coffee which themselves contribute to the overall flavor and aroma of the coffee.
U.S. Pat. No. 2,309,092 to Berry, et al. issued Jan. 26, 1943 describes a notable advance in the decaffeination art. According to this process, the extraction medium for caffeine is a water solution of green coffee water solubles, other than caffeine, at a concentration in equilibrium with the water soluble solids in the green coffee. This aqueous extract is continuously recycled through the green coffee and through a liquid-liquid extraction with a water-immiscible, organic caffeine solvent. This method produces decaffeinated coffee of superior flavor and aroma for beverage purposes due to the fact that the organic caffeine solvent does not come in direct contact with the green coffee beans.
Although the water extraction process described in U.S. Pat. No. 2,309,092 was a decided advance in the art, there still exists the need for further improving the quality of decaffeinated coffees such that coffee beverages prepared therefrom more nearly approximate their undecaffeinated counterparts in flavor and aroma.
It is accordingly an object of this invention to prepare decaffeinated coffees of improved quality.
It is another object of this invention to prepare decaffeinated coffees of improved quality by improvement on the water extraction process described in U.S. Pat. No. 2,309,092.